Apparatus for the manufacture of bricks

ABSTRACT

A string of brick material is extruded, and at least one surface of the string is engaged with one or more rollers having surface projections, to form depressions in the string surface. An instrument, such as a smooth-surfaced roller, is then applied to the depression-bearing surface, there being relative movement between the surface and instrument in a direction generally parallel to the surface. As a result, the depressions are deformed, giving the surface the appearance of a hand-molded brick. Thereafter, the string is cut into individual bricks. A filler may be introduced into the depressions prior to their deformation. The upper edges of the extruded string may be rounded, and the upper cut edges of the bricks may be deformed by the tool which cuts the string into individual bricks.

United States Patent van Daal Nov. 13, 1973 APPARATUS FOR THE MANUFACTURE OF BRICKS [76] Inventor: Hans van Daal, Geilenkirchen,

[30] Foreign Application Priority Data Mar. 17, 1971 Germany P 21 12 916.8

[52] US. Cl 425/296, 425/302, 425/304, 425/385 [51] Int. Cl. B28b l/29, B28b 3/12 [58] Field of Search 425/385, 304, 296, 425/302, 289, 307, 298, 299, 294

[56] References Cited UNITED STATES PATENTS 2,675,596 4/1954 Singer 425/385 X 734,124 7/1903 Frey 425/289 1,580,154 4/1926 Neher 425/385 X 1,631,220 6/1927 Nichols0n.... 425/385 1,454,731 5/1923 Francis 425/385 1,477,663 12/1923 Poston 425/304 X 1,207,272 12/1916 Buckley 425/385 X 2/1903 Frey 425/304 X 720,797 1,147,679 7/1915 Chrissinger 425/296 693,760 2/1902 Walker 425/289 Primary Examiner-.1. Spencer Overholser Assistant Examiner-B. D. Tobor AttorneyAlan H. Levine et a1.

[57] ABSTRACT A string of brick material is extruded, and at least one surface of the string is engaged with one or more rollers having surface projections, to form depressions in the string surface. An instrument, such as a smoothsurfaced roller, is then applied to the depressionbearing surface, there being relative movement between the surface and instrument in a direction generally parallel to the surface. As a result, the depressions are deformed, giving the surface the appearance of a hand-molded brick. Thereafter, the string is cut into individual bricks. A filler may be introduced into the depressions prior to their deformation. The upper edges of the extruded string may be rounded, and the upper cut edges of the bricks may be deformed by the tool which cuts the string into individual bricks.

6 Claims, 6 Drawing Figures 1 APPARATUS FOR THE MANUFACTURE OF BRICKS cally relates to such a method'and apparatus employing a profile roller for producing deformations in a surface of the string of brick material leaving the extrusion press, which surface may or may;not be sanded.

Bricks are used to provide building framework covering of high mechanical strength and weatherproof qual-' ity. According to the type of manufacture there are dis-' tinguished:

Machine bricks, which are made on extrusion presses and necessarily have-a uniform surface'texture, and

Hand-molded bricks, which are'thrown by hand into box molds and thereby acquire very individual surface characteristics.

While the machine bricks are produced by mass production, the naturally very much more expensive handmolded bricks are desirable for producing a more attractive framework covering.

Attempts to machine the surface of the string of brick material emerging from the extruder by rollers and thereby to imitate the typical surface structure of handmolded bricks mechanically have so far been without success. Dutch Patent Application No. 67 12494, laid open to public inspection on Mar. 14, 1969, discloses, for example, the practice of treating the surface, of the extrusion string with several profile rollers, movable upward and downward, under the control of various eccentrics. Dutch Patent Application 69 00124, laid open to public inspection on July 7, 1970, discloses turning the bricks, coming in the usual manner from the automatic cut-off units, with great expenditure in apparatus, in order to sand them from'all sides and thereby achieve a similarity to hand-molded bricks. These bricks, however, can' immediately be recognized as machine-bricks, even by the layman, since they show neitherthe'typical surface structure with its undercuts nor the rounded edges characteristic of the'manual production.

Underlying the invention is'the' problem of producing machine clinker bricks which cannot be distinguished from hand-molded bricks, even by specialists.

This problem is solved according to the invention by milling, i.e., applying a moving pressure to, the deformed surface of the extension string before the latter is cut up into individual bricks.

A further feature of the invention involves'introducing sand, sawdust, or other filler material into the surface deformations, with the aid-of a broom, prior to the milling step to produce various types of undercuts in the brick material surface.

The advantages achieved with the invention reside especially in the production of bricks, with the desired weight and/or material, which is not possible in the case of bricks made by hand.

An illustrative embodiment of the invention is represented in the drawings and is further described below with reference to the accompanying drawings, in which:

FIG. 1 is a side view of the entire apparatus;

FIG. 2 is a plan view of the entire apparatus;

FIG. 3 is a section through the extruded string along the line III-IlI of FIG. 1;

FIG. 4 is a section along the line lVlV of FIG. 1;

FIG. 5 is a section along the line V-V of FIG. 4, with cutting bow lowered; and

FIG. 6 is a perspective view of the various rollers of the apparatus.

The clay string 12, densely sanded according to known procedure, leaves the extrusion press 10 in the fonn 14 shown in FIG. 3, with rounded upper edges 16, which is obtained by corresponding choice of the mouthpiece of the extrusion press. This form is expedient so that the clay string can absorb the considerable pressures of the rollers which will act on it, and press it into the rectangular form. These rollers would severely deform the usual rectangular string.

The clay string, while still in a plastic state, is moved longitudinally and at least one profiled roller acts on the upper surface of the string. Further, at least one pair of profile rollers can treat the side surfaces. The diameters of therollers, their surface structure, the pressure on the string, and their position with respect to the string can be adapted to the particular requirements. In the embodiment represented in FIGS. 1 and 2, the rollers 18 and 20 are used for the treatment of the upper surface of the string. As can be seen from FIG. 6, the large roller 18 with its coarse surface projections, giving it a pronounced relief-type surface texture, makes deep scarsand gashes, in the string surface.

. The smaller roller 20 produces numerous shallower desurface structure, in large quantities much more' cheaply than hand-molded bricks. The apparatus required by the invention can easily be installed on already existing fabrication apparatus including an extrusion press. Moreover, any type of brick form can be used with the present invention by variation of the extrusion nozzles of the extrusion press, such as those developed for reasons of heat-insulation and saving of pressions. Thereupon, from a container 22, there may be spread on the string surface a filler such as, hay, sand, or'sawdust, which is then swept with a broom 24 into the cuts and depressions. The particular filler used causes different surface textures to be produced.

The surface thus treated is now milled, i.e., a'suitable instrument is used to apply a moving pressure to the surface, the direction of movement being generally parallel to the surface. In the present example, the instrument used is a small smooth roller 26, although a scraper or other device could also be used. The string moves beneath roller 26, and the high contact pressure between the upper depression-bearing surface and the roller causes the depressions to be deformed, thereby producing oblique cuts and undercuts in the string surface, this surface formation being typically found in hand-molded bricks.

The undercuts, folds, and incisions produced in this manner, whose variety can be varied at will by chang- 1 ing the profile,'diameter, and number of the rollers, yield surface structures that even a specialist cannot distinguish, or. can hardly distinguish, from those of hand-molded tiles or bricks. I

The side surfaces of the string can be treated in a similar manner, for which purpose in the present example two roller pairs 28 and 30 are employed.

A further characteristic feature of hand-molded bricks are the rounded upper edges yielded by the manner of production. To form these roundings there is mounted on the bow 34 of the automatic cutter 32, which cuts up the string into pieces 36 of any desired thickness, a strip 38 which extends in a downward curve into a sharp edge .40, as can be seen in FIG. 5. The height of the edge 40 can be adjusted by shifting and fastening the strip 38 using the screw 42 to conform to the particular height of the string or of the bricks.

When the bow 34 is lowered, the wire 44 cuts off a brick 36 from the string 12. Toward the end of the cutting operation, the sharp edge 40 of the strip 38 is pressed between the upper edges of the newly formed brick 36 and the string 12, and in the process rounds them off. Since this is repeated in each cutting operation, each brick is formed with rounded side edges.

This, however, is not the only way to round or break the upper edges of the bricks. It is possible, for example, to arrange on the automatic cutter a device which, offset in each case by one or more brick thicknesses with respect to the wire 44, in the course of the cutting movement beats a notch into the surface of the string. Thereafter, the wire 44 cuts through the notch, so as to achieve a rounding or breaking of the edges.

The combination of the surface texture, produced by milling, with the rounded side' edges, gives these machine made bricks such a similarity to hand-molded bricks that in a wall they can hardly be distinguished from each other even by specialists.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An apparatus for producing bricks each having at least one surface resembling that of a hand-molded brick, comprising:

a. an extruder for extruding a string of brick material, means forming part of said extruder for rounding the top surface of said string;

b. a roller having surface projections for engaging the rounded top surface of the moving string and forming depressions therein,

c. means for cutting said string into individual bricks, said cutting means including means spaced from the cutting edge for rounding off the cut upper edges of the individual bricks, and means for adjusting the spacing between the cutting edge and said rounding off means, and

d. an instrument between said roller and cutting means for applying a pressure against the depression-bearing surface of the moving string to deform the surface depressions and flatten the rounded top surface.

2. An apparatus as defined in claim 1 wherein said instrument is a roller.

I 3. An apparatus as defined in claim 2 wherein said roller has a smooth surface.

4. An apparatus as defined in claim 1 wherein said cutting means includes a bow, and a cutting element extending across said bow and having a cutting edge, and said rounding-off means includes a strip extending across said bow at a level above said cutting edge, and including means for adjusting the spacing between said strip and cutting edge.

5. An apparatus as defined in claim 4 wherein said strip has a V-shaped cross section terminating in a sharp lower edge.

6. An apparatus as defined in claim 5 wherein the converging edges of said strip are concave. 

1. An apparatus for producing bricks each having at least one surface resembling that of a hand-molded brick, comprising: a. an extruder for extruding a string of brick material, means forming part of said extruder for rounding the top surface of said string; b. a roller having surface projections for engaging the rounded top surface of the moving string and forming depressions therein, c. means for cutting said string into individual bricks, said cutting means including means spaced from the cutting edge for rounding off the cut upper edges of the individual bricks, and means for adjusting the spacing between the cutting edge and said rounding off means, and d. an instrument between said roller and cutting means for applying a pressure against the depression-bearing surface of the moving string to deform the surface depressions and flatten the rounded top surface.
 2. An apparatus as defined in claim 1 wherein said instrument is a roller.
 3. An apparatus as defined in claim 2 wherein said roller has a smooth surface.
 4. An apparatus as defined in claim 1 wherein said cutting means includes a bow, and a cutting element extending across said bow and having a cutting edge, and said rounding-off means includes a strip extending across said bow at a level above said cutting edge, and including means for adjusting the spacing between said strip and cutting edge.
 5. An apparatus as defined in claim 4 wherein said strip has a V-shaped cross section terminating in a sharp lower edge.
 6. An apparatus as defined in claim 5 wherein the converging edges of said strip are concave. 